Fix segfault

Author: iluuu1994

Zend/zend_vm_def.h

@@ -5899,6 +5899,7 @@ ZEND_VM_HANDLER(181, ZEND_FETCH_CLASS_CONSTANT, VAR|CONST|UNUSED|CLASS_FETCH, CO
 			// Enums require loading of all class constants to build the backed enum table
 			if (ce->ce_flags & ZEND_ACC_ENUM && ce->enum_backing_type != IS_UNDEF && ce->type == ZEND_USER_CLASS && !(ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 				if (UNEXPECTED(zend_update_class_constants(ce) == FAILURE)) {
+					ZVAL_UNDEF(EX_VAR(opline->result.var));
 					HANDLE_EXCEPTION();
 				}
 			}

Zend/zend_vm_execute.h

@@ -7068,6 +7068,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_CONS
 			// Enums require loading of all class constants to build the backed enum table
 			if (ce->ce_flags & ZEND_ACC_ENUM && ce->enum_backing_type != IS_UNDEF && ce->type == ZEND_USER_CLASS && !(ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 				if (UNEXPECTED(zend_update_class_constants(ce) == FAILURE)) {
+					ZVAL_UNDEF(EX_VAR(opline->result.var));
 					HANDLE_EXCEPTION();
 				}
 			}
@@ -24619,6 +24620,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_VAR_
 			// Enums require loading of all class constants to build the backed enum table
 			if (ce->ce_flags & ZEND_ACC_ENUM && ce->enum_backing_type != IS_UNDEF && ce->type == ZEND_USER_CLASS && !(ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 				if (UNEXPECTED(zend_update_class_constants(ce) == FAILURE)) {
+					ZVAL_UNDEF(EX_VAR(opline->result.var));
 					HANDLE_EXCEPTION();
 				}
 			}
@@ -33463,6 +33465,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_UNUS
 			// Enums require loading of all class constants to build the backed enum table
 			if (ce->ce_flags & ZEND_ACC_ENUM && ce->enum_backing_type != IS_UNDEF && ce->type == ZEND_USER_CLASS && !(ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 				if (UNEXPECTED(zend_update_class_constants(ce) == FAILURE)) {
+					ZVAL_UNDEF(EX_VAR(opline->result.var));
 					HANDLE_EXCEPTION();
 				}
 			}